Apparatus for assembling a multielement electron gun member



June 1970 HlDEHlKO YOSHlDA ETA!- 3,515,131

APPARATUS FOR ASSEMBLING A MULTIELEMENT ELECTRON GUN MEMBER Filed March18. 1968 2 Sheets-Sheet 1 FIG. 1B

June 23, 1970 HlDEHlKO-YOSHIDA ETAL APPARATUS FOR ASSEMBLING AMULTIELEMENT ELECTRON GUN MEMBER Filed March 18. 1968 2 Sheets-Sheet 2United States Patent US. Cl. 29-25.19 1 Claim ABSTRACT OF THE DISCLOSUREAn apparatus for assembling a multielement electron gun member wherein agauge provided with a plurality of grooves is fixed to a jig body, eachcentral rod is fitted into each groove in such a manner that theextensions of said rods intersect each other at a point, a supportmember is slidably engaged with the free end of each rod, thecircumferential surface of the support member being so constructed as tosecure the parts of each electron gun unit with spacers, and supportdevices are fitted to the jig body for locating said parts in theprescribed position.

The present invention relates to improvement in an apparatus forassembling a multielement electron gun member used in colour televisionpicture tubes and the like.

A triple electron gun member used in a colour television picture tube,for example, a shadow mask type picture tube is so constructed as tocause electron beams to be focussed at one point on the shadow mask. Insuch triple electron gun member, the direction of electron beams isdirectly determined by the electron gun member itself. However, toconstruct this member, it is required that the parts of each electrongun unit, namely, the cathode electrode and various grids thereof bespatially disposed along the central axis and also that these parts belocated exactly in the prescribed position to cause the central axes ofthese electron gun units to intersect each other at one point on theshadow mask.

Such type of electron gun member is generally prepared using anassembling means. However, the drawbacks associated with the prior artassembling means were, for example, that the direction of electron beamswas very likely to be off the mask due to the cause origimating with thestructure of said assembling means itself. Consequently it has beendesired to improve the structure of such means in order to eliminatesuch shortcomings.

The present invention is intended to eliminate the aforementioneddrawbacks incurred with the prior art assembling means.

The invention can be more fully understood from the following detaileddescription when taking into consideration the accompanying drawings, inwhich:

FIGS. 1A and 1B are profiles of an embodiment of the present inventionwith parts thereof broken away;

FIG. 2 is a section on line IIII of the embodiment shown in FIG. 1A; and

FIG. 3 is a perspective of the main part of the above embodiment.

On the base of a jig body 1 there are provided at equal intervals threesupport arms 2, 2, 2 extending upwardly from the periphery thereof. Tothe upper inner side of the support arms 2, 2, 2 is fitted a gauge 3having an inverted truncated conical shape. On the outer circumferentialsurface of the gauge 3 are perforated at equal intervals in a concentricline three V-shaped grooves 3,516,131 Patented June 23, 1970 a a and aextending in the direction of a bus. These V-shaped grooves a a and aare respectively disposed between the support arms 2, 2, 2. Into thesegrooves are fitted the bottom ends of central rods b b and b;,. Thecentral axes of these rods respectively define an angle 0 with thecentral axis A-A of the jig body 1, namely, these rods are arranged insuch a manner that the central axes of three electron gun unitsintersect each other at one point in their extension. To one side of thesupport arms 2, 2, 2 are pivoted keep plates c c and 0;, in a manner tocause one end thereof respectively to be rotated in a horizontal planearound axles 4, 4, 4, and to the other side of the support arms 2, 2, 2are similarly pivoted levers d d and d;, at one end so as to be rotatedin a vertical plane. At the upper ends of the levers d d and d areprovided knobs 5, 5, 5. Below the support arms 2, 2, 2 are pivotedsupport devices e e and 6 so as to be rotated around horizontal axles 6,6, 6 in a vertical plane radially in relation to the central axis of thegauge 3. At the upper end of the support devices e e and e arepositioned cylindrical members 7. Into the hole of each cylindricalmember 7 is slidably fitted a sliding rod 8. This sliding rod 8 isprovided with a guide pin 10 to be fitted into an L-shaped slot 9perforated in the cylindrical member 7. At the upper end of the slidingrod 8 is located a handle (grip) 11. Also to the lower end of thesliding rod 8 is fitted a receiving means 13 shaped to fit a supportplate 12 for a cathode tube. Between the receiving means 13 and thecylindrical member 7 is inserted a compression spring 14. The upper endsof the central rods b b and 12 are closely fitted into the hollow areasprovided at the bottom ends of the locating support members f f and fThe upper outer circumferential surfaces of these support members aregently tapered (see FIG. 3), and into each of the circumferentialsurfaces are tightly fitted the parts of each electron gun unit such asfour grid electrodes 15, 16, 17 and 18 by the aid of, for example, fourspacers 19, 20, 21 and 22. The axial centre of these parts of theelectron gun is aligned with that of the locating support members, andthe spacers keep the parts at the prescribed intervals in relation tothe direction of the axial centre. The bottom ends of the locatingsupport members are securely held on the bottom plane of the truncatedconical gauge 3. This gauge is supported by the support arms 2, 2, 2 insuch a manner that downward from the bottom end of each central rod inthe direction of the central axis there is allowed as long a free spaceas above the central rod. On the lower outer circumferential surfaces ofeach locating support member is provided a magnet 23 to attract theinside of the respective support devices e e and e;,.

There will now be described the method of employing the apparatus of thepresent invention. First, the support devices e e and e are opened bycausing them to rotate outwardly as indicated by a dotted line in FIG.1A. Raise the sliding rod 8 using the handle 11 up to the positiondenoted by a dotted line in FIG. 1A against the elastic force of thespring 14. Rotate the sliding rod 8 to cause the guide pin 10 to engagewith the upper bend of the slot 9. Fit a support plate 12 for thecathode tube into a means 13 for receiving the bottom end of the slidingrod 8. Insert the central rods b b and b into the grooves a a and aperforated in the circumferential surface of the gauge 3. Rotate thekeep plates c c and c to the position shown in FIG. 2, to the positionshown by the dotted line of FIG. 3 so as to hold the central rods b band h in the grooves. Rotate the levers d d and d upward using the knobs5, 5, 5 so as to cause the keep plates c c and 0 to stand at rest byengagement with the levers as shown by the solid line of FIG. 3.Slidably engage the hollow locating support members f f and 3 f with theupper parts of the central rods [1 b and b On each outer circumferentialsurface of the locating support members f f and f;, are arranged a gridelec trode 18, a spacer 22, a grid electrode 18, a spacer 21, a gridelectrode 16, a spacer 20, a grid electrode 15 and a spacer 19 in theorder mentioned in such a manner that these electron gun parts aresecured in place as if clamped by the spacers. Rotate the supportdevices e e and e3 to the position shown by the solid line of FIG. 1A soas to align the central axes of the sliding rods 8 with those of thecentral rods b b and b At this time the magnets 23 attract the insidesof the support devices e e and 2 so that these devices are kept in sucha position as shown in FIG. 1B. Rotate the sliding rod 8 by the knob 11to remove the guide pin 10 from the L-shaped slot 9. Then the elasticforce of the spring 14 causes the receiving means 13 and the cathodetube support plate 12 to press the spacer 19 so as to ensure that thegrid electrodes and spacers are all pressed to the prescribed position.The outermost surface of the gauge 3, namely, the bottom plane of thetruncated cone is flat and controls the positioning of the bottoms ofthe locating support members f f and f and consequently the positioningof the electron gun parts in the X-Y plane. Using an insulating glassdepositing means (not shown), three electron gun units are fixed inplace by fusing to each of three support rods consisting of slenderglass rods or the like the adjacent ends of foot plates 31, 32, 33, 34and 35 previously fitted to the cathode tube support plate 12 and fourgrid electrodes 15, 1 6, 17 and 18 respectively.

The removal from the jig body 1 of a triple electron gun member thusassembled is carried out as follows. First, raise the sliding rod 8against the elastic force of the spring 14 using the knob 11, androtatethe rod to engage the guide pin 10 with the upper bend of the slot 9,thereby to remove the receiving means 13 from the cathode tube supportplate 12. Rotate the support devices e e and e to the position shown bythe dotted line of FIG. 1B. Rotate the levers d d and d downward usingthe knobs 5, 5, to release the keep plates c c and c Since the keepplates are rotated outwardly, namely, to the position indicated by thedotted line of FIG. 3, the central rods b b and b are also disengaged.Press downward a protrusion 30 at the bottom ends of the central rods bb and b using a tool (not shown) to let fall the rods to the positionshown by the dotted line of FIG. 1B. Then the upper parts of the rodsare separated from the locating support members f f and f so that thetriple electron gun member can be drawn out sidewise along with thesupport members. Pull the support members downward from the tripleelectron member, and the spacers 19, 20, 21 and 22 sidewise therefrom.Then there will be obtained a free triple electron gun member.

As mentioned above, the present invention enables the triple electrongun member to be easily taken out of an assembling means, withoutdisplacing the direction of each electron gun unit, but with theprescribed arrangement thereof accurately maintained.

While the invention has been described in connection with, somepreferred embodiments thereof, the invention is not limited thereto andincludes any modifications and alterations which fall within the truespirit and scope of the invention as defined in the appended claim.

What is claimed is:

'1. An apparatus for assembling a multielement electron gun membercomprising a jig body; a plurality of locating support members eachconsisting of a hollow rod having a tapered upper end portion fittedinto the inner diameters of the parts of each electron gun unit and ahollow lower end portion and intended to arrange the parts of eachelectron gun unit so as to cause the central axes thereof to be alignedtogether; a plurality of spacers for securing the parts of each electrongun unit at the prescribed intervals in relation to the central axis; aplurality of central rods each having the upper end removably fittedinto the lower end of the locating support member and the central axisaligned with those of the electron gun parts; a gauge of an invertedtruncated conical shape having a plurality of grooves provided parallelwith the truncated conical bus and at equal intervals in a concentricline and mounted on the jig body in such a manner that downward from thelower end of each central rod along the central axis thereof there isallowed as long a free space as above the upper end thereof, said lowerend of each central rod being fitted into each groove and said lower endof each locating support member being disposed in close contact with thebottom plane of the truncated conical gauge; a means for fixing thecentral rod to the prescribed positions in the groove; and a pluralityof support devices for locating the parts of ,each electron gun unit byremovably pressing the upper ends of said electron gun parts downwardalong the central axis thereof, said support device having the lower endpivoted to the jig body and being arranged to rotate in a vertical planeincluding the groove rod radially in relation to the central axis of thegauge.

References Cited UNITED STATES PATENTS 2,914,317 11/1959 Miller et al29-2519 XR 2,985,947 5/1961 Curd et al. 29-25.19 3,434,819 3/1969Merchant et al 2925.19 XR JOHN F. CAMPBELL, Primary Examiner R. B.LAZARUS, Assistant Examiner US. Cl. X.R. 269254, 126

